Rheostat with rotating arm



J. P. SMITH, JR

RHEOSTAT WITH ROTATING ARM 'March 29, 1949.

Filed Jan. 50, 1947 FIG.4-

OUT

Elm 0mm FIG-.5

Patented Mar. 29, 1949 RHEOSTAT WITH ROTATING ARM John P. Smith, Jr., Verona, N. 1., assignor to The Daven Company, Newark, N. J., a corporation of New Jersey Application January 30, 1947, Serial No. 725,333

4 Claims.

This invention relates to sound transmission and/or recording and more particularly to a dubbing control for dubbing or cutting in or out certain sounds or passages during recording. In recording sounds for program transmission it has been the practice heretofore to fade in the desired sound at the correct place in the program by means of a quick twist on a gain control, which was not very satisfactory since the control could not be moved fast enough to catch the start of the sound. To overcome the defects of this method a lever-type key switch was employed to switch in the desired sound at the correct place. The use of the lever-type key switch permitted suificient quickness in cutting in the sound but usually caused a pop or click in the program recording, due to transients, particularly so if the signal had already started.

An object of the present invention is to provide a dubbing control for cutting certain passages or sounds into a program recording which control will eliminate the disadvantages of both the previously employed methods above referred to and which new and improved control can be operated as quickly as a key switch yet has the advantage of fading in the signal or sound passage in correct decibel steps and thereby eliminate any pop or click in the recording.

With these and other objects in view, as may appear from the accompanying specification, the invention consists of various features of construction and combination of parts, which will be first described in connection with the accompanying drawings, showing a dubbing control for cutting in or out passages in sound recording of a preferred form embodying the invention, and the features forming the invention will be specifically pointed out in the claims.

In the drawings- Figure 1 is an improved perspective view of the dubbing control.

Figure 2 is an edge elevation of the improved dubbing control having a part broken away.

Figure 3 is a top plan of the dubbing control.

Figure 4 is a horizontal section through the dubbing control taken on the line 4-4 of Figure 2.

Figure 5 is a diagrammatic view of the electrical circuit of the clubbing control.

Referring more particularly to the drawings, the improved dubbing control comprises a substantially U-shaped carrying frame I which has an attenuator 2 positioned between the side legs 3 and 4 thereof and attached to the carrying frame I in any suitable manner.

The attenuator 2 is flat and as shown in the drawings is rectangular in shape, although it need not necessarily be limited to a rectangular shape. The attenuator carrying body 5, which is made of suitable insulating material, has a slipring contact 6 carried thereby at its inner end and in relatively close proximity to a plurality of spaced contacts I as carried by the body 5 of the attenuator. The slip-rin cont-act 6 is connected as shown in diagrammatic Figure 5 of the drawings to the in connection 8 of the attenuator structure 2 by suitable wiring 9 While the spaced contacts I are connected through resistance coils I 0 and H with each other and with the c connection I 2 of the attenuator.

A novel form of switch lever structure is carried by the U-shaped carrying frame I and projects through a slot I 5 in the cross bar iii of the U- shaped carrying frame. The key switch structure I! includes a flat carrying body I8 to which an operating handle I 9 is attached in any suitable manner. The carrying body I8 is pivotally connected by means of pivot pin 20 and ears 2| to the cross bar l6 of the U-shaped frame. The body It! of the switch lever I! has an L-shaped contact finger carrying member 22 attached thereto in any suitable manner, which is constructed of insulating material. A plurality of resilient or spring contact fingers 23 and 24 are carried by the member 22 and they contact respectively the slip-ring 6 and contacts 1, contacting the different spaced contacts as the key switch lever structure I! is moved upon its pivot for fading in signals or sound passages into a program being recorded, in correct decibel steps quickly, and efliciently, without any pop or click in the recording.

The body I8 of the key switch lever structure IT has ears or stop members 25 formed thereon at its lower upper edges which contact the inner surface of the cross bar N5 of th carrying frame I to form stops for limiting the movement of the key switch to provide proper terminal limitation of the movement of the contact fingers 23 and 24 on the slip ring 6 and the spaced contacts 1.

It will be understood that the invention is not to be limited to the specific construction or arrangement of parts shown, but that they may be widely modified within the invention defined by the claims.

What is claimed is:

1. A dubbing control for use in fading in signals or sounds in a program recording comprising a substantially U-shaped carrying frame, a flat attenuator carried by said carrying frame and having a slip ring contact and a plurality of spaced individual contacts arranged in cooperative relation on said attenuator, the cross bar of said U-shaped carrying frame having depending ears formed thereon, a switch lever pivotally supported by said depending ears, a contact finger carrying member of insulating material attached to said switch lever, a plurality of spring contacts carried by said insulating member for engagement with said slip ring, and a second plurality of spring contact fingers carried by said insulating member for engagement with said spaced indi-,

vidual contacts.

2. A dubbing control for use in fading in sig nals or sounds in a program recording comprising a substantially U-shaped carrying frame, a fiat attenuator carried by said carrying frame and having a slip ring contact and a plurality of spaced individual contacts arranged in cooperative relation on said attenuator, the cross bar of said U-shaped carrying frame having depending ears formed thereon, a switch lever pivotally supported by said depending ears, a contact finger carrying member of insulating material attached to said switch lever, a plurality of spring contacts carried by said insulating member for engagement with said slip ring, and a second plurality of spring contact fingers carried by said insulating member for engagement with said spaced individual contacts, said pivoted switch lever having stop members formed thereon for engagement with the U-shaped frame to limit the pivoted movement of the switch lever.

3. A dubbing control for use in fading in signals or sounds in a program recording comprising a substantially U-shaped carrying frame, a

flat attenuator carried by said carrying frame and having a slip ring contact and a plurality of spaced individual contacts arranged in cooperative relation on said attenuator, said attenuator having its inner end spaced from the cross bar of said U-shaped carrying frame, a switch lever carried by the cross bar and extending into the space within the frame between the inner end of the attenuator and the cross bar, and a contact member carried by said switch lever for engagement with said contacts.

4. A dubbing control for use in fading in signals or sounds in a program recording comprising a substantially U-shaped carrying frame, a fiat attenuator carried by said carrying frame and having a slip ring contact and a plurality of spaced individual contacts arranged in cooperative relation on said attenuator, said attenuator having its inner end spaced from the cross bar of said U-shaped carrying frame, a switch lever carried by the cross bar and extending into the space within the frame between the inner end of the attenuator and the cross bar, and a contact member carried by said switch lever for engagement with said contacts, said pivoted switch lever having stop members formed thereon for engagement with the U-shaped frame to limit the pivotal movement of the switch lever.

JOHN P. SMITH, JR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

